1. Field of the Invention
The present invention relates to an information providing apparatus, an information providing method, a storage medium, and a computer program for providing information associated with a real image taken by a camera or the like. In particular, the present invention relates to an information providing apparatus, an information providing method, a storage medium, and a computer program for providing a real image taken by a camera by associating the real image with position information obtained by using a global positioning system (GPS) or the like.
More specifically, the present invention relates to an information providing apparatus, an information providing method, a storage medium, and a computer program for providing a real image taken by a camera together with predetermined information. In particular, the present invention relates to an information providing apparatus, information providing method, a storage medium, and a computer program, in which information relating position information is added to a real image taken by a camera so as to provide image information in which the relationship between the recording location and added information can be easily understood.
2. Description of the Related Art
A global positioning system (GPS) has been developed in order to calculate the current position on the earth. In this system, the current position is calculated by receiving radio waves transmitted from three or more low-earth-orbit satellites orbiting around the earth. Generally, radio waves from about four to twelve satellites can be constantly received on the ground. The current position can be detected by calculating the phases of the radio waves. A measurement error at each time is 300 to 100 m.
GPSs were originally designed in order to detect the position of a vehicle, ship, aircraft, and so on for military use. However, the technology was put to civilian use so that GPSs have been widely used recently. Also, various services, in which a position measuring service using a GPS or the like is combined with other information processing services or information providing services, have been designed.
For example, vehicle-mounted navigation systems, which display road information in real time by combining a position measured by a GPS or the like and map information, have become widespread. In this type of navigation system, the position of a running vehicle is detected by using a GPS or the like and a road map of the corresponding area is read from map data so that the position of the vehicle is superposed on the road map in a display device such as a liquid crystal display.
Further, navigation systems, which not only display a road map together with the position of a vehicle but also call attention to a driver and display high-value images by using computing ability of a computer, are being developed.
For example, Japanese Unexamined Patent Application Publication No. 10-7989 discloses a forward image display device for displaying three-dimensional image including roads by using a three-dimensional computer graphics technique so as to display information to which a driver must pay attention, such as there is a curve, a road becomes narrower, or there is a slope, such that the driver can easily understand the information.
GPSs are used by combining them with various information apparatuses other than vehicles. For example, by combining a GPS with a video information recording device such as a video camera, a video recording position can be noticed or an obtained image can be managed.
For example, Japanese Unexamined Patent Application Publication No. 11-205725, which has been assigned to the applicant of the present application, discloses a video information recording/reproducing apparatus for performing recording/reproducing by associating a recording position with the video information recorded position. In this video information recording/reproducing apparatus, position information can be used for managing video. That is, by simultaneously displaying a recorded video and a map indicating the recording position, the position where the video is recorded can be displayed when reproducing is performed. Also, by specifying the recording position on the map, the video recorded at the specified position can be easily obtained.
News distribution to mobile phones is an example of an information providing service using position information. In this service, a receiving station of mobile phones is identified and information is distributed as news.
However, much of information distributed in an information providing service performed currently is not linked to information of the environment around a user. Thus, it is difficult to determine the position from which information is provided.
Also, in a navigation system using map information, image information displayed in an information providing apparatus is provided such that the image information is placed on a two-dimensional map or a three-dimensional map. However, the information is quite different from a scene which the user is actually seeing. Thus, it is difficult for the user to immediately find a desired information object from among the presented image information.
Further, even if a very realistic virtual space can be realized so that information can be provided by an information providing apparatus, it is difficult to understand the relationship between the provided information and buildings in a real image, because the direction of the display of the information providing apparatus is different from the direction of the user's gaze.
In order to realize a very realistic virtual space, a lot of texture and accurate modeling are required. Furthermore, if the virtual space is not updated frequently, the difference between the virtual space and a scene which is actually seen becomes big.